{"id":196,"date":"2023-10-26T16:32:31","date_gmt":"2023-10-26T08:32:31","guid":{"rendered":"http:\/\/ai.gitpp.com\/?p=196"},"modified":"2023-10-27T09:34:26","modified_gmt":"2023-10-27T01:34:26","slug":"5-%e6%95%b0%e6%8d%ae%e7%bb%93%e6%9e%84","status":"publish","type":"post","link":"http:\/\/ai.gitpp.com\/index.php\/2023\/10\/26\/5-%e6%95%b0%e6%8d%ae%e7%bb%93%e6%9e%84\/","title":{"rendered":"\u300aPython\u5165\u95e8\u6559\u7a0b\u300b5. \u6570\u636e\u7ed3\u6784"},"content":{"rendered":"\n
    \n
  1. \u5f00\u80c3\u83dc<\/li>\n\n\n\n
  2. \u4f7f\u7528 Python \u89e3\u91ca\u5668<\/a><\/li>\n\n\n\n
  3. \u975e\u6b63\u5f0f\u4ecb\u7ecdPython<\/a><\/li>\n\n\n\n
  4. \u6df1\u5165\u6d41\u7a0b\u63a7\u5236<\/a><\/li>\n\n\n\n
  5. \u6570\u636e\u7ed3\u6784<\/a><\/li>\n\n\n\n
  6. \u6a21\u5757<\/a><\/li>\n\n\n\n
  7. \u8f93\u5165\u548c\u8f93\u51fa<\/a><\/li>\n\n\n\n
  8. \u9519\u8bef\u548c\u5f02\u5e38<\/a><\/li>\n\n\n\n
  9. \u7c7b<\/a><\/li>\n\n\n\n
  10. \u6807\u51c6\u5e93\u7684\u7b80\u660e\u4ecb\u7ecd<\/a><\/li>\n\n\n\n
  11. \u6807\u51c6\u5e93\u7684\u7b80\u660e\u4ecb\u7ecd\uff08\u7b2c\u4e8c\u90e8\u5206\uff09<\/a><\/li>\n\n\n\n
  12. \u73b0\u5728\u5e72\u4ec0\u4e48?<\/a><\/li>\n\n\n\n
  13. \u4ea4\u4e92\u5f0f\u8f93\u5165\u7f16\u8f91\u53ca\u5386\u53f2\u66ff\u4ee3<\/a><\/li>\n\n\n\n
  14. \u6d6e\u70b9\u7b97\u672f: \u95ee\u9898\u548c\u9650\u5236<\/a><\/li>\n<\/ol>\n\n\n\n

    # \u5269\u4f59\u7684\u961f\u5217, \u5b83\u6309\u7167\u8fdb\u5165\u7684\u987a\u5e8f\u6392\u5217<\/em> deque([‘Michael’, ‘Terry’, ‘Graham’])<\/p>\n\n\n\n

    5.1.3. \u5217\u8868\u63a8\u5bfc\u5f0f<\/a><\/h3>\n\n\n\n

    \u5217\u8868\u63a8\u5bfc\u5f0f\u63d0\u4f9b\u4e86\u4ece\u5e8f\u5217\u4e2d\u521b\u5efa\u5217\u8868\u7684\u7b80\u4fbf\u9014\u5f84. \u901a\u5e38\u7a0b\u5e8f\u4f1a\u5bf9\u5e8f\u5217\u7684\u6bcf\u4e00\u4e2a\u5143\u7d20\u505a\u4e9b\u64cd\u4f5c,\u5e76\u4ee5\u5176\u7ed3\u679c\u4f5c\u4e3a\u65b0\u5217\u8868\u7684\u5143\u7d20, \u6216\u8005\u6839\u636e\u6307\u5b9a\u7684\u6761\u4ef6\u6765\u521b\u5efa\u5b50\u5e8f\u5217.<\/p>\n\n\n\n

    \u800c\u5217\u8868\u63a8\u5bfc\u5f0f\u7684\u7ed3\u6784\u662f, \u5728\u4e00\u4e2a\u65b9\u62ec\u53f7\u91cc, \u9996\u5148\u662f\u4e00\u4e2a\u8868\u8fbe\u5f0f, \u968f\u540e\u662f\u4e00\u4e2a for<\/code><\/a> \u5b50\u53e5, \u7136\u540e\u662f\u96f6\u4e2a\u6216\u66f4\u591a\u7684 for<\/code><\/a> \u6216 if<\/code><\/a> \u5b50\u53e5. \u7ed3\u679c\u5c06\u662f\u901a\u8fc7\u8ba1\u7b97 for<\/code><\/a> \u548c if<\/code><\/a> \u5b50\u53e5\u6765\u83b7\u5f97\u7684\u4e00\u4e2a\u5217\u8868. \u5982\u679c\u8981\u4f7f\u8868\u8fbe\u5f0f\u63a8\u5bfc\u5f0f\u51fa\u5143\u7ec4, \u5c31\u5fc5\u987b\u7528\u5706\u62ec\u53f7.<\/p>\n\n\n\n

    \u8fd9\u91cc\u6211\u4eec\u5c06\u4e00\u4e2a\u6570\u5b57\u5217\u8868\u6bcf\u4e2a\u5143\u7d20\u7ffb\u4e09\u500d\u4ece\u800c\u751f\u6210\u4e00\u4e2a\u65b0\u5217\u8868:>>> <\/strong>vec = [2, 4, 6] >>> <\/strong>[3*x for<\/strong> x in<\/strong> vec] [6, 12, 18]<\/p>\n\n\n\n

    \u73b0\u5728\u52a0\u70b9\u513f\u5c0f\u82b1\u6837:>>> <\/strong>[[x, x**2] for<\/strong> x in<\/strong> vec] [[2, 4], [4, 16], [6, 36]]<\/p>\n\n\n\n

    \u8fd9\u91cc\u6211\u4eec\u5bf9\u5e8f\u5217\u91cc\u6bcf\u4e00\u9879\u9010\u4e2a\u8c03\u7528\u67d0\u65b9\u6cd5:>>> <\/strong>freshfruit = [‘ banana’, ‘ loganberry ‘, ‘passion fruit ‘] >>> <\/strong>[weapon.strip() for<\/strong> weapon in<\/strong> freshfruit] [‘banana’, ‘loganberry’, ‘passion fruit’]<\/p>\n\n\n\n

    \u6211\u4eec\u53ef\u4ee5\u7528 if<\/code><\/a> \u5b50\u53e5\u6765\u8fdb\u884c\u8fc7\u6ee4:>>> <\/strong>[3*x for<\/strong> x in<\/strong> vec if<\/strong> x > 3] [12, 18] >>> <\/strong>[3*x for<\/strong> x in<\/strong> vec if<\/strong> x < 2] []<\/p>\n\n\n\n

    \u5143\u7ec4\u7ecf\u5e38\u80fd\u4e0d\u7528\u5706\u62ec\u53f7\u800c\u521b\u5efa, \u4f46\u8fd9\u91cc\u4e0d\u884c:>>> <\/strong>[x, x**2 for<\/strong> x in<\/strong> vec] # error – parens required for tuples<\/em> File “<stdin>”, line 1, in ? [x, x**2 for x in vec] ^ SyntaxError: invalid syntax >>> <\/strong>[(x, x**2) for<\/strong> x in<\/strong> vec] [(2, 4), (4, 16), (6, 36)]<\/p>\n\n\n\n

    \u8fd9\u91cc\u662f\u4e00\u4e9b\u5faa\u73af\u7684\u5d4c\u5957\u548c\u5176\u5b83\u6280\u5de7\u7684\u6f14\u793a:>>> <\/strong>vec1 = [2, 4, 6] >>> <\/strong>vec2 = [4, 3, -9] >>> <\/strong>[x*y for<\/strong> x in<\/strong> vec1 for<\/strong> y in<\/strong> vec2] [8, 6, -18, 16, 12, -36, 24, 18, -54] >>> <\/strong>[x+y for<\/strong> x in<\/strong> vec1 for<\/strong> y in<\/strong> vec2] [6, 5, -7, 8, 7, -5, 10, 9, -3] >>> <\/strong>[vec1[i]*vec2[i] for<\/strong> i in<\/strong> range(len(vec1))] [8, 12, -54]<\/p>\n\n\n\n

    \u5217\u8868\u63a8\u5bfc\u5f0f\u53ef\u4f7f\u7528\u590d\u6742\u7684\u8868\u8fbe\u5f0f\u548c\u5d4c\u5957\u7684\u51fd\u5f0f:>>> <\/strong>[str(round(355\/113, i)) for<\/strong> i in<\/strong> range(1, 6)] [‘3.1’, ‘3.14’, ‘3.142’, ‘3.1416’, ‘3.14159’]<\/p>\n\n\n\n

    5.1.4. \u5d4c\u5957\u5217\u8868\u63a8\u5bfc\u5f0f<\/a><\/h3>\n\n\n\n

    \u5982\u679c\u4f60\u53d7\u7684\u4e86\u7684\u8bdd, \u5176\u5b9e\u5217\u8868\u63a8\u5bfc\u5f0f\u662f\u53ef\u4ee5\u5d4c\u5957\u7684. \u5b83\u7684\u786e\u662f\u4e2a\u5f3a\u5927\u7684\u5de5\u5177, \u4f46 \u2013 \u5c31\u50cf\u6240\u6709\u5f3a\u5927\u7684\u5de5\u5177\u4e00\u6837 \u2013 \u9700\u8981\u88ab\u5c0f\u5fc3\u5730\u4f7f\u7528,<\/p>\n\n\n\n

    \u8003\u8651\u4e0b\u9762\u7684\u4f8b\u5b50, \u6709\u4e00\u4e2a 3×3 \u7684\u77e9\u9635, \u5b58\u50a8\u4e3a\u4e00\u4e2a\u5305\u542b\u4e09\u4e2a\u5217\u8868\u7684\u5217\u8868, \u6bcf\u4e00\u884c\u4e00\u4e2a\u5217\u8868:>>> <\/strong>mat = [ …<\/strong> [1, 2, 3], …<\/strong> [4, 5, 6], …<\/strong> [7, 8, 9], …<\/strong> ]<\/p>\n\n\n\n

    \u73b0\u5728, \u5982\u679c\u4f60\u60f3\u4ea4\u6362\u884c\u548c\u5217, \u53ef\u4ee5\u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f:>>> <\/strong>print([[row[i] for<\/strong> row in<\/strong> mat] for<\/strong> i in<\/strong> [0, 1, 2]]) [[1, 4, 7], [2, 5, 8], [3, 6, 9]]<\/p>\n\n\n\n

    \u4f7f\u7528*\u5d4c\u5957*\u5217\u8868\u63a8\u5bfc\u5f0f\u65f6\u7279\u522b\u9700\u8981\u6ce8\u610f:<\/p>\n\n\n\n

    \n

    \u4ece\u53f3\u81f3\u5de6\u5730\u9605\u8bfb\u5d4c\u5957\u5217\u8868\u63a8\u5bfc\u5f0f\u66f4\u5bb9\u6613\u7406\u89e3.<\/p>\n<\/blockquote>\n\n\n\n

    \u8be5\u4ee3\u7801\u7684\u5197\u957f\u7248\u672c, \u5c31\u660e\u767d\u5730\u8868\u8ff0\u4e86\u6d41\u7a0b:for<\/strong> i in<\/strong> [0, 1, 2]: for<\/strong> row in<\/strong> mat: print(row[i], end=””) print()<\/p>\n\n\n\n

    \u73b0\u5b9e\u4e2d, \u4f60\u5e94\u5f53\u9009\u62e9\u5185\u5efa\u51fd\u5f0f\u6765\u5904\u7406\u590d\u6742\u6d41\u7a0b. \u8fd9\u91cc, \u51fd\u5f0f zip()<\/code><\/a> \u5c31\u975e\u5e38\u597d\u7528.>>> <\/strong>list(zip(*mat)) [(1, 4, 7), (2, 5, 8), (3, 6, 9)]<\/p>\n\n\n\n

    \u53c2\u89c1 \u53c2\u6570\u5217\u8868\u89e3\u5305<\/a> \u4e86\u89e3\u672c\u884c\u4e2d\u661f\u53f7\u7684\u8be6\u7ec6\u5185\u5bb9.<\/p>\n\n\n\n

    5.2. del<\/code><\/a> \u8bed\u53e5<\/a><\/h2>\n\n\n\n

    \u8fd9\u6709\u4e00\u79cd\u901a\u8fc7\u7ed9\u5b9a\u7d22\u5f15\u800c\u4e0d\u662f\u503c, \u6765\u5220\u9664\u5217\u8868\u4e2d\u9879\u7684\u65b9\u6cd5: \u7528 del<\/code><\/a> \u8bed\u53e5. \u5b83\u4e0e\u8fd4\u56de\u4e00\u4e2a\u503c\u7684 pop()<\/code> \u65b9\u6cd5\u4e0d\u540c. del<\/code><\/a> \u8bed\u53e5\u4e5f\u53ef\u4ee5\u79fb\u9664\u5217\u8868\u4e2d\u7684\u5207\u7247, \u6216\u8005\u6e05\u9664\u6574\u4e2a\u5217\u8868 (\u4e4b\u524d\u6211\u4eec\u901a\u8fc7\u7ed9\u5207\u7247\u8d4b\u503c\u4e3a\u7a7a\u5217\u8868\u6765\u5b8c\u6210\u8fd9\u70b9). \u4f8b\u5982:>>> <\/strong>a = [-1, 1, 66.25, 333, 333, 1234.5] >>> <\/strong>del<\/strong> a[0] >>> <\/strong>a [1, 66.25, 333, 333, 1234.5] >>> <\/strong>del<\/strong> a[2:4] >>> <\/strong>a [1, 66.25, 1234.5] >>> <\/strong>del<\/strong> a[:] >>> <\/strong>a []<\/p>\n\n\n\n

    del<\/code><\/a> \u4e5f\u53ef\u4ee5\u7528\u4e8e\u5220\u9664\u53d8\u91cf\u5b9e\u4f53:>>> <\/strong>del<\/strong> a<\/p>\n\n\n\n

    \u5728\u8fd9\u4e4b\u540e\u5f15\u7528 a<\/code> \u7684\u8bdd\u4f1a\u4ea7\u751f\u4e00\u4e2a\u9519\u8bef (\u81f3\u5c11\u5230\u7ed9\u5b83\u8d4b\u53e6\u4e00\u4e2a\u503c\u4e4b\u524d). \u6211\u4eec\u5c06\u5728\u540e\u9762\u627e\u5230 del<\/code><\/a> \u7684\u5176\u5b83\u7528\u6cd5.<\/p>\n\n\n\n

    5.3. \u5143\u7ec4\u548c\u5e8f\u5217<\/a><\/h2>\n\n\n\n

    \u6211\u4eec\u770b\u5230\u5217\u8868\u548c\u5b57\u4e32\u6709\u5f88\u591a\u901a\u7528\u7684\u5c5e\u6027, \u4f8b\u5982\u7d22\u5f15\u548c\u5207\u7247\u64cd\u4f5c. \u5b83\u4eec\u662f \u5e8f\u5217<\/strong> \u6570\u636e\u7c7b\u578b\u7684\u4e24\u4e2a\u4f8b\u5b50 (\u53c2\u8003 Sequence Types \u2014 str, bytes, bytearray, list, tuple, range<\/a>). Python \u4f5c\u4e3a\u4e00\u95e8\u8fdb\u5316\u4e2d\u7684\u8bed\u8a00, \u53ef\u80fd\u8fd8\u6709\u5176\u5b83\u5e8f\u5217\u7c7b\u578b\u4f1a\u88ab\u52a0\u5165. \u8fd9\u91cc\u5c31\u6709\u53e6\u4e00\u79cd\u6807\u51c6\u5e8f\u5217\u6570\u636e\u7c7b\u578b: \u5143\u7ec4<\/strong> .<\/p>\n\n\n\n

    \u5143\u7ec4\u7531\u82e5\u5e72\u9017\u53f7\u5206\u9694\u7684\u503c\u7ec4\u6210, \u4f8b\u5982:>>> <\/strong>t = 12345, 54321, ‘hello!’ >>> <\/strong>t[0] 12345 >>> <\/strong>t (12345, 54321, ‘hello!’) >>> <\/strong># Tuples may be nested:<\/em>… <\/strong>u = t, (1, 2, 3, 4, 5) >>> <\/strong>u ((12345, 54321, ‘hello!’), (1, 2, 3, 4, 5))<\/p>\n\n\n\n

    \u5982\u4f60\u6240\u89c1, \u5143\u7ec4\u8f93\u51fa\u65f6\u7528\u5706\u62ec\u53f7\u5305\u56f4, \u4ee5\u4fbf\u6b63\u786e\u8868\u8fbe\u5143\u7ec4\u7684\u5d4c\u5957; \u5728\u8f93\u5165\u65f6\u5706\u62ec\u53f7\u53ef\u52a0\u53ef\u4e0d\u52a0, \u4e0d\u8fc7\u5706\u62ec\u53f7\u7ecf\u5e38\u662f\u5fc5\u8981\u7684 (\u7279\u522b\u662f\u5f53\u5143\u7ec4\u662f\u66f4\u5927\u7684\u8868\u8fbe\u5f0f\u7684\u4e00\u90e8\u5206\u65f6).<\/p>\n\n\n\n

    \u5143\u7ec4\u6709\u8bb8\u591a\u7528\u9014. \u4f8b\u5982: (x, y) \u5750\u6807\u5bf9, \u6570\u636e\u5e93\u91cc\u7684\u5458\u5de5\u8bb0\u5f55\u7b49. \u5143\u7ec4\u540c\u5b57\u4e32\u90fd\u662f\u4e0d\u53ef\u53d8\u7684: \u65e0\u6cd5\u5bf9\u5143\u7ec4\u6307\u5b9a\u9879\u8fdb\u884c\u8d4b\u503c (\u5c3d\u7ba1\u53ef\u901a\u8fc7\u5207\u7247\u548c\u8fde\u63a5\u6765\u6a21\u62df\u8fd9\u4e2a\u64cd\u4f5c). \u5143\u7ec4\u4e2d\u53ef\u4ee5\u5305\u542b\u53ef\u53d8\u7684\u5bf9\u8c61, \u5982\u5217\u8868.<\/p>\n\n\n\n

    \u6784\u9020\u5305\u542b 0 \u6216 1 \u4e2a\u9879\u7684\u5143\u7ec4\u662f\u4e2a\u7279\u6b8a\u95ee\u9898: \u8bed\u6cd5\u4e0a\u4e3a\u4e86\u9002\u5e94\u8fd9\u4e00\u60c5\u51b5,\u6709\u4e9b\u989d\u5916\u7684\u89c4\u5219. \u7a7a\u5143\u7ec4\u7531\u4e00\u5bf9\u7a7a\u7684\u5706\u62ec\u53f7\u6784\u9020; \u4e00\u4e2a\u9879\u7684\u5143\u7ec4\u7531\u4e00\u4e2a\u503c\u540e\u9762\u8ddf\u7740\u4e00\u4e2a\u9017\u53f7\u6784\u9020 (\u628a\u4e00\u4e2a\u503c\u653e\u5165\u4e00\u5bf9\u5706\u62ec\u53f7\u91cc\u5e76\u4e0d\u8db3\u4ee5\u6784\u9020\u4e00\u4e2a\u5143\u7ec4). \u4e11\u964b, \u4f46\u6709\u6548. \u4f8b\u5982:>>> <\/strong>empty = () >>> <\/strong>singleton = ‘hello’, # <– \u6ce8\u610f\u540e\u9762\u7684\u9017\u53f7<\/em>>>> <\/strong>len(empty) 0 >>> <\/strong>len(singleton) 1 >>> <\/strong>singleton (‘hello’,)<\/p>\n\n\n\n

    \u8bed\u53e5 t = 12345, 54321, 'hello!'<\/code> \u662f \u5143\u7ec4\u6253\u5305<\/strong> \u7684\u4e00\u4e2a\u4f8b\u5b50: \u503c 12345<\/code>, 54321<\/code> \u548c 'hello!'<\/code> \u88ab\u6253\u5305\u8fdb\u4e00\u4e2a\u5143\u7ec4. \u53cd\u8fc7\u6765, \u8fd9\u4e2a\u64cd\u4f5c\u4e5f\u662f\u53ef\u884c\u7684:>>> <\/strong>x, y, z = t<\/p>\n\n\n\n

    \u8fd9\u79cd\u5bf9\u53f3\u4fa7\u4efb\u4e00\u5e8f\u5217\u7684\u5904\u7406\u5f88\u5408\u9002\u79f0\u4e3a \u5e8f\u5217\u89e3\u5305<\/strong> . \u5e8f\u5217\u89e3\u5305\u65f6\u8981\u6c42\u7b49\u53f7\u5de6\u8fb9\u7684\u503c\u4e2a\u6570\u4e0e\u53f3\u8fb9\u5e8f\u5217\u5143\u7d20\u4e2a\u6570\u76f8\u7b49. \u6ce8\u610f, \u591a\u91cd\u8d4b\u503c\u5176\u5b9e\u662f\u8054\u5408\u4f7f\u7528\u4e86\u5143\u7ec4\u6253\u5305\u548c\u5e8f\u5217\u89e3\u5305. (\u867d\u7136\u5143\u7ec4\u548c\u5217\u8868\u90fd\u7b97\u5e8f\u5217,\u4f46\u662f\u5fc5\u987b\u6709\u6240\u4e0d\u540c)<\/p>\n\n\n\n

    5.4. \u96c6\u5408(Set)<\/a><\/h2>\n\n\n\n

    Python \u8fd8\u5305\u542b\u4e86 \u96c6\u5408(set)<\/em> \u6570\u636e\u7c7b\u578b. \u96c6\u5408\u662f\u79cd\u65e0\u5e8f\u4e0d\u91cd\u590d\u7684\u5143\u7d20\u96c6. \u57fa\u672c\u7528\u9014\u5305\u62ec\u6210\u5458\u5173\u7cfb\u6d4b\u8bd5\u548c\u91cd\u590d\u6761\u76ee\u6d88\u9664. \u96c6\u5408\u5bf9\u8c61\u4e5f\u652f\u6301\u5408(union),\u4ea4(intersection), \u5dee(difference), \u548c\u5bf9\u79f0\u5dee(sysmmetric difference)\u7b49\u6570\u5b66\u64cd\u4f5c.<\/p>\n\n\n\n

    \u82b1\u62ec\u53f7\u6216\u51fd\u5f0f set()<\/code><\/a> \u53ef\u7528\u4e8e\u521b\u5efa\u96c6\u5408. \u6ce8\u610f: \u521b\u5efa\u4e00\u4e2a\u7a7a\u96c6\u5408\u53ea\u80fd\u4f7f\u7528 set()<\/code>, \u800c\u4e0d\u80fd\u4f7f\u7528 {}<\/code>; \u540e\u8005\u662f\u521b\u5efa\u4e00\u4e2a\u7a7a\u5b57\u5178, \u5b57\u5178\u6211\u4eec\u4f1a\u5728\u4e0b\u4e00\u8282\u91cc\u8ba8\u8bba.<\/p>\n\n\n\n

    \u4ee5\u4e0b\u662f\u7b80\u660e\u793a\u8303:>>> <\/strong>basket = {‘apple’, ‘orange’, ‘apple’, ‘pear’, ‘orange’, ‘banana’} >>> <\/strong>print(basket) # \u91cd\u590d\u7684\u88ab\u79fb\u9664\u4e86<\/em> {‘orange’, ‘banana’, ‘pear’, ‘apple’} >>> <\/strong>‘orange’ in<\/strong> basket # \u5feb\u901f\u6210\u5458\u5173\u7cfb\u6d4b\u8bd5<\/em> True >>> <\/strong>‘crabgrass’ in<\/strong> basket False >>> <\/strong># \u5728\u4e24\u4e2a\u5355\u8bcd\u7684\u4e0d\u91cd\u590d\u7684\u5b57\u6bcd\u91cc\u6f14\u793a\u96c6\u5408\u64cd\u4f5c<\/em>…<\/strong>>>> <\/strong>a = set(‘abracadabra’) >>> <\/strong>b = set(‘alacazam’) >>> <\/strong>a # a \u4e2d\u7684\u4e0d\u91cd\u590d\u5b57\u6bcd<\/em> {‘a’, ‘r’, ‘b’, ‘c’, ‘d’} >>> <\/strong>a – b # a \u4e2d\u6709\u800c b \u4e2d\u6ca1\u6709\u7684\u5b57\u6bcd<\/em> {‘r’, ‘d’, ‘b’} >>> <\/strong>a | b # \u65e2\u6709 a \u7684\u5b57\u6bcd\u53c8\u6709 b \u7684\u5b57\u6bcd<\/em> {‘a’, ‘c’, ‘r’, ‘d’, ‘b’, ‘m’, ‘z’, ‘l’} >>> <\/strong>a & b # a \u548c b \u4e2d\u90fd\u6709\u7684\u5b57\u6bcd<\/em> {‘a’, ‘c’} >>> <\/strong>a ^ b # a \u6216 b \u4e2d\u53ea\u6709\u4e00\u4e2a\u6709\u7684\u5b57\u6bcd<\/em> {‘r’, ‘d’, ‘b’, ‘m’, ‘z’, ‘l’}<\/p>\n\n\n\n

    \u5c31\u50cf \u5217\u8868<\/a>, \u96c6\u5408\u4e5f\u652f\u6301\u63a8\u5bfc\u5f0f:>>> <\/strong>a = {x for<\/strong> x in<\/strong> ‘abracadabra’ if<\/strong> x not<\/strong>in<\/strong> ‘abc’} >>> <\/strong>a {‘r’, ‘d’}<\/p>\n\n\n\n

    5.5. \u5b57\u5178<\/a><\/h2>\n\n\n\n

    Python \u4e2d\u53e6\u4e00\u5f88\u6709\u7528\u7684\u5185\u5efa\u6570\u636e\u7c7b\u578b\u4e3a \u5b57\u5178<\/em> (\u53c2\u8003 Mapping Types \u2014 dict<\/a>). \u5728\u5176\u5b83\u8bed\u8a00\u4e2d\u5b57\u5178\u4e00\u822c\u88ab\u53eb\u505a \u201c\u5173\u8054\u5b58\u50a8\u201d \u6216 \u201c\u5173\u8054\u6570\u7ec4\u201d. \u4e0e\u4f7f\u7528\u67d0\u4e2a\u8303\u56f4\u4f5c\u4e3a\u7d22\u5f15\u7684\u5e8f\u5217\u4e0d\u4e00\u6837, \u5b57\u5178\u901a\u8fc7 \u952e<\/em> \u6765\u7d22\u5f15, \u800c\u952e\u53ef\u4ee5\u662f\u4efb\u610f\u4e0d\u53ef\u53d8\u7c7b\u578b; \u901a\u5e38\u7528\u5b57\u7b26\u4e32\u548c\u6570\u5b57\u4f5c\u4e3a\u952e. \u5982\u679c\u5143\u7ec4\u53ea\u5305\u542b\u5b57\u7b26\u4e32\u548c\u6570\u5b57, \u5143\u7ec4\u4e5f\u53ef\u4ee5\u4f5c\u4e3a\u952e; \u4f46\u662f, \u5f53\u5143\u7ec4\u76f4\u63a5\u6216\u95f4\u63a5\u5730\u5305\u542b\u53ef\u53d8\u5bf9\u8c61\u65f6, \u5c31\u4e0d\u80fd\u7528\u4f5c\u4e00\u4e2a\u952e. \u4e0d\u80fd\u4f7f\u7528\u5217\u8868\u4f5c\u4e3a\u952e, \u56e0\u4e3a\u5217\u8868\u53ef\u4ee5\u901a\u8fc7\u7d22\u5f15, \u5207\u7247, \u6216\u5982 append()<\/code> \u548c extend()<\/code> \u65b9\u6cd5\u539f\u5730\u8d4b\u503c\u800c\u88ab\u6539\u53d8.<\/p>\n\n\n\n

    \u6700\u597d\u628a\u5b57\u5178\u770b\u6210\u662f\u4e00\u4e2a\u6ca1\u6709\u987a\u5e8f\u7684 \u952e:\u503c<\/em> \u5bf9\u96c6\u5408, \u952e\u5fc5\u987b\u662f\u552f\u4e00\u7684 (\u5728\u4e00\u4e2a\u5b57\u5178\u91cc). \u4e00\u5bf9\u82b1\u62ec\u53f7\u521b\u5efa\u4e00\u4e2a\u7a7a\u5b57\u5178: {}<\/code>. \u5728\u62ec\u53f7\u4e2d\u95f4\u653e\u7f6e\u7684\u4ee5\u9017\u53f7\u5206\u9694\u7684 \u952e:\u503c\u5bf9<\/code> \u5217\u8868\u5c31\u662f\u5b57\u5178\u7684\u521d\u59cb \u952e:\u503c\u5bf9<\/code>. \u8fd9\u4e5f\u662f\u5b57\u5178\u8f93\u51fa\u65f6\u7684\u683c\u5f0f.<\/p>\n\n\n\n

    \u5b57\u5178\u6700\u4e3b\u8981\u7684\u64cd\u4f5c\u662f\u901a\u8fc7\u67d0\u952e\u5b58\u50a8\u4e00\u4e2a\u503c, \u4ee5\u53ca\u4ece\u7ed9\u5b9a\u7684\u952e\u91cc\u63d0\u53d6\u5b83\u7684\u503c. \u4f7f\u7528 del<\/code> \u53ef\u4ee5\u5220\u9664\u4e00\u4e2a\u952e:\u503c\u5bf9. \u5982\u679c\u4f60\u4f7f\u7528\u4e00\u4e2a\u5df2\u88ab\u4f7f\u7528\u7684\u952e\u8fdb\u884c\u5b58\u50a8\u64cd\u4f5c, \u8be5\u952e\u7684\u65e7\u503c\u5c31\u6ca1\u6709\u4e86. \u4f7f\u7528\u4e00\u4e2a\u4e0d\u5b58\u5728\u7684\u952e\u63d0\u53d6\u503c\u4f1a\u4ea7\u751f\u4e00\u4e2a\u9519\u8bef.<\/p>\n\n\n\n

    \u5728\u4e00\u4e2a\u5b57\u5178\u4e0a\u6267\u884c list(d.keys())<\/code> \u8fd4\u56de\u8be5\u5b57\u5178\u4e2d\u6240\u4f7f\u7528\u952e\u7684\u5217\u8868, \u8be5\u5217\u8868\u7684\u987a\u5e8f\u4e0d\u786e\u5b9a (\u5982\u679c\u9700\u8981\u6709\u5e8f, \u53ea\u8981\u4f7f\u7528 sorted(d.keys())<\/code>). [1]<\/a> \u8981\u68c0\u67e5\u67d0\u4e00\u4e2a\u952e\u662f\u5426\u5728\u5b57\u5178\u91cc, \u4f7f\u7528 in<\/code><\/a> \u5173\u952e\u5b57.<\/p>\n\n\n\n

    \u8fd9\u662f\u4e00\u4e2a\u4f7f\u7528\u5b57\u5178\u7684\u5c0f\u4f8b\u5b50:>>> <\/strong>tel = {‘jack’: 4098, ‘sape’: 4139} >>> <\/strong>tel[‘guido’] = 4127 >>> <\/strong>tel {‘sape’: 4139, ‘guido’: 4127, ‘jack’: 4098} >>> <\/strong>tel[‘jack’] 4098 >>> <\/strong>del<\/strong> tel[‘sape’] >>> <\/strong>tel[‘irv’] = 4127 >>> <\/strong>tel {‘guido’: 4127, ‘irv’: 4127, ‘jack’: 4098} >>> <\/strong>list(tel.keys()) [‘irv’, ‘guido’, ‘jack’] >>> <\/strong>sorted(tel.keys()) [‘guido’, ‘irv’, ‘jack’] >>> <\/strong>‘guido’ in<\/strong> tel True >>> <\/strong>‘jack’ not<\/strong>in<\/strong> tel False<\/p>\n\n\n\n

    \u6784\u9020\u5668 dict()<\/code><\/a> \u4ece\u952e-\u503c\u5bf9\u5e8f\u5217\u91cc\u76f4\u63a5\u751f\u6210\u5b57\u5178,\u5982\u679c\u6709\u56fa\u5b9a\u7684\u6a21\u5f0f,\u53ef\u5728\u5217\u8868\u63a8\u5bfc\u5f0f\u6307\u5b9a\u7279\u5b9a\u7684\u952e\u503c\u5bf9:>>> <\/strong>dict([(‘sape’, 4139), (‘guido’, 4127), (‘jack’, 4098)]) {‘sape’: 4139, ‘jack’: 4098, ‘guido’: 4127} >>> <\/strong>dict([(x, x**2) for<\/strong> x in<\/strong> (2, 4, 6)]) # \u4f7f\u7528\u5217\u8868\u63a8\u5bfc\u5f0f<\/em> {2: 4, 4: 16, 6: 36}<\/p>\n\n\n\n

    \u5728\u672c\u6559\u7a0b\u540e\u9762\u7684\u7ae0\u8282, \u4f1a\u5b66\u4e60\u5230\u751f\u6210\u5668\u8868\u8fbe\u5f0f, \u8fd9\u66f4\u9002\u4e8e\u4e3a dict()<\/code><\/a> \u6784\u9020\u5668\u751f\u6210\u952e-\u503c\u5bf9\u5e8f\u5217. \u82e5\u952e\u4e3a\u5b57\u7b26\u4e32, \u6709\u65f6\u7528\u5173\u952e\u5b57\u53c2\u6570\u6307\u5b9a\u952e-\u503c\u5bf9\u66f4\u4e3a\u7b80\u5355:>>> <\/strong>dict(sape=4139, guido=4127, jack=4098) {‘sape’: 4139, ‘jack’: 4098, ‘guido’: 4127}<\/p>\n\n\n\n

    5.6. \u904d\u5386\u6280\u5de7<\/a><\/h2>\n\n\n\n

    \u5f53\u5bf9\u5b57\u5178\u904d\u5386\u65f6, \u53ef\u7528 items()<\/code> \u65b9\u6cd5\u540c\u65f6\u53d6\u56de\u952e\u548c\u5bf9\u5e94\u7684\u503c.>>> <\/strong>knights = {‘gallahad’: ‘the pure’, ‘robin’: ‘the brave’} >>> <\/strong>for<\/strong> k, v in<\/strong> knights.items(): …<\/strong> print(k, v) …<\/strong> gallahad the pure robin the brave<\/p>\n\n\n\n

    \u5bf9\u5e8f\u5217\u904d\u5386\u65f6, \u53ef\u4ee5\u4f7f\u7528 enumerate()<\/code><\/a> \u51fd\u5f0f\u6765\u540c\u65f6\u53d6\u56de\u4f4d\u7f6e\u7d22\u5f15\u548c\u76f8\u5e94\u7684\u503c.>>> <\/strong>for<\/strong> i, v in<\/strong> enumerate([‘tic’, ‘tac’, ‘toe’]): …<\/strong> print(i, v) …<\/strong> 0 tic 1 tac 2 toe<\/p>\n\n\n\n

    \u540c\u65f6\u5bf9\u4e24\u4e2a\u6216\u66f4\u591a\u7684\u5e8f\u5217\u8fdb\u884c\u904d\u5386\u65f6, \u53ef\u7528 zip()<\/code><\/a> \u8fdb\u884c\u7ec4\u5408>>> <\/strong>questions = [‘name’, ‘quest’, ‘favorite color’] >>> <\/strong>answers = [‘lancelot’, ‘the holy grail’, ‘blue’] >>> <\/strong>for<\/strong> q, a in<\/strong> zip(questions, answers): …<\/strong> print(‘What is your {0}<\/em>? It is {1}<\/em>.’.format(q, a)) …<\/strong> What is your name? It is lancelot. What is your quest? It is the holy grail. What is your favorite color? It is blue.<\/p>\n\n\n\n

    \u53cd\u5411\u904d\u5386\u5e8f\u5217\u65f6, \u5148\u6307\u5b9a\u8fd9\u4e2a\u5e8f\u5217, \u7136\u540e\u8c03\u7528 reversed()<\/code><\/a> \u51fd\u5f0f>>> <\/strong>for<\/strong> i in<\/strong> reversed(range(1, 10, 2)): …<\/strong> print(i) …<\/strong> 9 7 5 3 1<\/p>\n\n\n\n

    \u60f3\u6709\u5e8f\u5730\u904d\u5386\u4e00\u4e2a\u5e8f\u5217, \u7528 sorted()<\/code><\/a> \u51fd\u5f0f\u8fd4\u56de\u6392\u5e8f\u540e\u7684\u5e8f\u5217,\u539f\u5e8f\u5217\u5c06\u4e0d\u88ab\u89e6\u53ca>>> <\/strong>basket = [‘apple’, ‘orange’, ‘apple’, ‘pear’, ‘orange’, ‘banana’] >>> <\/strong>for<\/strong> f in<\/strong> sorted(set(basket)): …<\/strong> print(f) …<\/strong> apple banana orange pear<\/p>\n\n\n\n

    5.7. \u6df1\u5165\u6761\u4ef6\u63a7\u5236<\/a><\/h2>\n\n\n\n

    \u5728 while<\/code> \u548c if<\/code> \u8bed\u53e5\u4e2d\u4f7f\u7528\u7684\u6761\u4ef6\u53ef\u4ee5\u5305\u542b\u4efb\u4f55\u64cd\u4f5c\u7b26, \u800c\u4e0d\u4ec5\u4ec5\u662f\u6bd4\u8f83.<\/p>\n\n\n\n